docstr: Test flattening an iterable with different values: str, bool, int, float, complex.
          
docstr_tok: ["Test","flattening","an","iterable","with","different","values",":","str",",","bool",",","int",",","float",",","complex","."]
code: def test_flatten(self):
      """Test flattening an iterable with different values: str, bool, int, float, complex."""
      test_cases = []
      test_cases.append(
          {"input": ["aa", "bb", "cc"], "golden": ["aa", "bb", "cc"]}
      )
      test_cases.append(
          {"input": ["aa", ["bb", "cc"]], "golden": ["aa", "bb", "cc"]}
      )
      test_cases.append(
          {
              "input": ["aa", [["bb"], [["cc"]]]],
              "golden": ["aa", "bb", "cc"],
          }
      )
      test_cases.append(
          {
              "input": ["aa", [[1, 2], [[3]], 4]],
              "golden": ["aa", 1, 2, 3, 4],
          }
      )
      test_cases.append(
          {
              "input": [True, [2.5, 2.0 + 1j]],
              "golden": [True, 2.5, 2.0 + 1j],
          }
      )
  
      for n, test_case in enumerate(test_cases):
          assert (
              flatten(test_case["input"]) == test_case["golden"]
          ), f"Test case {n} failed!"
  
file_path: NeMo/tests/collections/common/test_utils.py
imports: import os
  import string
  from contextlib import contextmanager
  from pathlib import Path
  from unittest import mock
  import numpy
  import pytest
  from nemo.collections.common.parts.preprocessing.manifest import get_full_path, is_tarred_dataset
  from nemo.collections.common.parts.utils import flatten
label_desc: Use image node_id 1 for calling the TestListUtils obj's underlying member method code with example usage: obj.test_flatten() without return types